deps: update dependency com.fasterxml.jackson:jackson-bom to v2.12.0 (#225)

Author: renovate-bot

pom.xml

@@ -73,7 +73,7 @@
     <opencensus.version>0.24.0</opencensus.version>
     <findbugs.version>3.0.2</findbugs.version>
     <errorprone.version>2.4.0</errorprone.version>
-    <jackson.version>2.11.3</jackson.version>
+    <jackson.version>2.12.0</jackson.version>
   </properties>
 
   <dependencyManagement>